There are no related applications.
The present invention relates to an apparatus for visually indicating the open and closed position of a valve having a linear moving valve stem.
It is often difficult to determine at a glance whether a valve is open or closed. This problem is of particular concern in consumer goods, such as with valves on propane gas tanks, where harmful gases could escape without notice and potentially cause serious injury. Known types of indicating devises are generally not well suited for use in valve-containing consumer goods because these indicators are typically integrated with the valve assembly and/or contain a number of moving parts which increase the possibility of malfunction and also increase the cost of production.
Known inventions include those in which the valve indicator is part of the valve handle assembly. For example, U.S. Pat. No. 3,910,308 describes a valve indicator consisting of a knurled valve handle having windows that expose an on/off color indicator of an interior ring operating by means of a spring and ball bearing mechanism.
Other known indicator devices function by attachment to the valve stem or actuator stem. U.S. Pat. No. 5,469,805 discloses a valve position indicator fitted to the drive shaft of a valve actuator. The indicator has a sleeve interposed between an inner cylinder and an outer cylinder and arranged such that rotation of the actuator rotates the inner cylinder and causes the sleeve to slide between the inner and outer cylinders allowing a different color to be visible when the valve is open or closed.
Another known mechanism of operation for valve position indicators is by attachment of the indicator to the valve bonnet. U.S. No. Pat. 2,485,942 discloses an indicator comprised of contrasting color vanes, one affixed to the valve bonnet and the other responsive to valve stem movement. When the valve stem is moved, one vane slides over the other to indicate whether the valve is open or closed.
Each of the aforementioned inventions illustrates the disadvantages of known mechanisms for valve position indicators. These indicators operate by use of moving parts, which are additional to the valve mechanism itself. Additional moving parts not only increase costs of production, but could also potentially fail, leading possible error on the part of the operator and the need to replace the entire valve assembly.
The present invention is directed to a valve indicator wherein the open/closed position of the valve is indicated by the visible appearance of one or two color bands below the hand wheel on a linear moving valve stem. Although the present invention will be described with particular reference to propane gas tank valves, it will be appreciated that the invention has broader applications and may be used with other types of valves having a valve stem that moves linearly from the open to closed position and/or in other environments. The invention is comprised of a hand wheel assembly with a hand grip having peripheral sidewalls and a downward depending annular sleeve wherein the hand wheel assembly is attached to a linear moving valve stem which operates to open and close the valve. A grommet stratified into one or more color bands is attached to and rests on the valve bonnet adjacent to the point where the valve stem enters the valve bonnet. As the valve is closed, the length of the valve stem shortens, drawing the annular sleeve of the hand wheel assembly down over the grommet to obscure one or more layers of the grommet""s color bands from vision, indicating that the valve is in the closed position. As the valve is opened, the length of the valve stem becomes longer, moving the annular sleeve of the hand wheel away from the grommet, thus exposing one or more layers of the grommet""s color band, indicating that the valve is in the open position.
In a preferred embodiment, the indicating means of the present invention is utilized in a propane gas tank valve.
It is an object of the present invention to provide a visual signal on a valve to indicate that a valve is open or closed.
It is a further object of the present invention to provide an indicator that is advantageously suited for use in consumer goods containing valves.
It is an additional object of the present invention to provide an inexpensive means to provide a visual valve position indication.
It is another object of the present invention to provide visual position indicating means on a valve without the addition of moving parts to facilitate manufacturing.
It is yet another object of the present invention to enhance the safety of a manual valve by providing visual indication of the valve open position.